Association between renal insufficiency and lesion characteristics of posterior reversible encephalopathy syndrome.

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is characterized by cerebral blood flow dysregulation and the blood-brain barrier (BBB) disruption. While renal insufficiency has been considered a factor in BBB fragility, the relationship between renal insufficiency and the PRES lesions volume remains unclear. METHODS: This observational study was performed retrospectively. PRES patients were categorized into two groups with renal insufficiency, defined as an estimated glomerular filtration rate (eGFR) of less than 60 mL/min/1.73m2 on the day of symptom occurrence. Lesion volume was measured using fluid-attenuated inversion recovery (FLAIR) imaging, and the brain was divided into nine regions. The volume of the parietal-occipital-temporal lobe was considered typical, while the other six regions were labeled as atypical. RESULTS: The study included 200 patients, of whom 94 (47%) had renal insufficiency. Patients with renal insufficiency had a larger lesion volume (144.7 ± 125.2 cc) compared to those without renal insufficiency (110.5 ± 93.2 cc; p = 0.032); particularly in the atypical lesions volume (49.2 ± 65.0 vs. 29.2 ± 44.3 cc; p = 0.013). However, there was no difference in the reversibility of the lesions (35.2 ± 67.5 vs. 18.8 ± 33.4 cc; p = 0.129). Multiple regression analysis revealed that decreases in eGFR (ß = -0.34, 95% CI -0.62-0.05, p = 0.020) were positively associated with total lesion volume. CONCLUSION: Our findings suggest that PRES patients with renal insufficiency experience more severe lesion volumes, likely due to the atypical brain regions involvement. The lesions involving atypical regions may have a similar pathophysiology to typical lesions, as the PRES lesions reversibility was found to be similar between individuals with and without renal insufficiency.

Explanatory Power and Prognostic Implications of Factors Associated with Troponin Elevation in Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: We investigated the impact of comorbidity burden on troponin elevation, with separate consideration of neurological conditions, in patients with acute ischemic stroke (AIS). METHODS: This prospective, observational cohort study consecutively enrolled patients with AIS for 2 years. Serum cardiac troponin I was repeatedly measured, and disease-related biomarkers were collected for diagnosis of preassigned comorbidities, including atrial fibrillation (AF), ischemic heart disease (IHD), myocardial hypertrophy (MH), heart failure (HF), renal insufficiency (RI), and active cancer. The severity of neurological deficits and insular cortical ischemic lesions were assessed as neurological conditions. Adjusted associations between these factors and troponin elevation were determined using a multivariate ordinal logistic regression model and area under the receiver operating characteristic curve (AUC). Cox proportional hazards model was used to determine the prognostic significance of comorbidity beyond neurological conditions. RESULTS: Among 1,092 patients (66.5±12.4 years, 63.3% male), 145 (13.3%) and 335 (30.7%) had elevated (≥0.040 ng/mL) and minimally-elevated (0.040-0.010 ng/mL) troponin, respectively. In the adjusted analysis, AF, MH, HF, RI, active cancer, and neurological deficits were associated with troponin elevation. The multivariate model with six comorbidities and two neurological conditions exhibited an AUC of 0.729 (95% confidence interval [CI], 0.698-0.759). In Cox regression, AF, IHD, and HF were associated with adverse cardio-cerebrovascular events, whereas HF and active cancer were associated with mortality. CONCLUSION: Troponin elevation in patients with AIS can be explained by the burden of comorbidities in combination with neurological status, which explains the prognostic significance of troponin assay.

Transcranial Doppler as a Screening Tool for High-Risk Patent Foramen Ovale in Cryptogenic Stroke.

BACKGROUND AND PURPOSE: The identification of high-risk patent foramen ovale (PFO) is important for selecting suitable patients for PFO closure to prevent recurrent stroke in those with cryptogenic stroke. We aimed to evaluate the predictability of transcranial Doppler (TCD) in diagnosing high-risk PFO compared with that of transesophageal echocardiography (TEE), which is not feasible for some stroke patients. METHODS: We retrospectively reviewed the data of 461 cryptogenic stroke patients who underwent TEE and TCD for PFO evaluation. High-risk PFO on TEE was defined as PFO with atrial septal aneurysm (phasic septal excursion ≥10 mm) or large PFO (≥2 mm). Spencer grading of right-to-left shunt was used to classify the amount of shunt on TCD. RESULTS: PFO on TEE was observed for 242 (52.5%) patients, and high-risk PFO was detected for 123 (26.7%) patients. However, PFO on TCD was observed for 336 (72.9%) patients. Among patients with significant shunt (Spencer grade III or higher) who underwent TCD after Valsalva maneuver (VM), 60.0% of patients had high-risk PFO. However, only 5.3% of patients had high-risk PFO among those without significant shunt. Receiver operating characteristic curves showed that significant shunt after VM had higher predictability (AUC = .876, 95% CI: .843-.905) for detecting the high-risk PFO compared with the predictability based on significant shunt at rest (AUC = .718, 95% CI: .674-.759). (P<.0001 for the differences between two AUCs). CONCLUSIONS: TCD is a good screening tool for evaluating high-risk PFO. VM is important for the evaluation of PFO. Patients with minimal or no shunt on TCD after VM are unlikely to have high-risk PFO.

Are Genetic Variants Associated with the Location of Cerebral Arterial Lesions in Stroke Patients?

BACKGROUND: Genetic variants may play a role in determining the location of cerebral atherosclerosis. We aimed to investigate the association between RNF213, MMP2, and genetic polymorphisms linked to vascular tortuosity with the location of cerebral arterial atherosclerosis. METHODS: A prospective case-control study was conducted on patients with ischemic stroke and age- and sex-matched stroke-free controls. The stroke patients were categorized into those with intracranial artery atherosclerosis (ICAS), extracranial artery atherosclerosis (ECAS), and small vessel occlusion (SVO). Six single nucleotide polymorphisms (SNPs) including rs2118181 (FBN1), rs2179357 (SLC2A10), rs1036095 (TGFBR2), rs243865 (MMP2), rs1800470 (TGFB1), and rs112735431 (RNF213) were analyzed with the TaqMan Genotyping Assay, and the distribution of genotypes across groups was compared. RESULTS: None of the 6 SNPs were associated with stroke on comparing the 449 stroke patients (71 with ECAS, 169 with ICAS, and 209 with SVO) to the 447 controls. In the subgroup analysis, the adjusted odds ratios (aORs) for age and sex indicated a significant association between rs112735431 and ICAS in the allele comparison analysis and in the additive and dominant model analyses. rs112735431 was associated with anterior circulation involvement and increased burden of cerebral atherosclerosis. rs2179357 was significantly associated with ICAS in the recessive model analysis, and rs1800470 was significantly associated with ECAS in the recessive model analysis when compared to controls. CONCLUSION: rs112735431 was associated with ICAS and increased atherosclerosis burden in Korean stroke patients. Further studies are needed to elucidate the role of rs112735431 and to confirm the association of rs2179357 and rs1800470 with cerebral atherosclerosis.

Repeatability of amide proton transfer-weighted signals in the brain according to clinical condition and anatomical location.

OBJECTIVES: To investigate whether clinical condition, imaging session, and locations affect repeatability of amide proton transfer-weighted (APTw) magnetic resonance imaging (MRI) in the brain. MATERIALS AND METHODS: Three APTw MRI data sets were acquired, involving two intrasession scans and one intersession scan for 19 healthy, 15 glioma, and 12 acute stroke adult participants (mean age 53.8, 54.6, and 68.5, respectively) on a 3T MR scanner. The mean APTw signals from five locations in healthy brain (supratentorial and infratentorial locations) and from entire tumor and stroke lesions (supratentorial location) were calculated. The within-subject coefficient of variation (wCV) and intraclass correlation coefficient (ICC) were calculated for each clinical conditions, image sessions, and anatomic locations. Differences in APTw signals between sessions were analyzed using repeated-measures analysis of variance. RESULTS: The ICC and wCV were 0.96 (95% confidence interval [CI], 0.91-0.99) and 16.1 (12.6-21.3) in glioma, 0.93 (0.82-0.98) and 15.0 (11.4-20.6) in stroke, and 0.84 (0.72-0.91) and 34.0 (28.7-41.0) in healthy brain. There were no significant differences in APTw signal between three sessions, irrespective of disease condition and location. The ICC and wCV were 0.85 (0.68-0.94) and 27.4 (21.8-35.6) in supratentorial, and 0.44 (- 0.18 to 0.76) and 32.7 (25.9 to 42.9) in infratentorial locations. There were significant differences in APTw signal between supra- (mean, 0.49%; 95% CI, 0.38-0.61) and infratentorial locations (1.09%, 0.98-1.20; p < 0.001). CONCLUSION: The repeatability of APTw signal was excellent in supratentorial locations, while it was poor in infratentorial locations due to severe B0 inhomogeneity and susceptibility which affects MTR asymmetry. KEY POINTS: • In supratentorial locations, APTw MRI showed excellent intrasession and intersession repeatability in brains of healthy controls and patients with glioma, as well as in stroke-affected regions. • APTw MRI showed excellent repeatability in supratentorial locations, but poor repeatability in infratentorial locations. • Considering poor repeatability in the infratentorial locations, the use of APTw MRI in longitudinal assessment in infratentorial locations is not indicated.

Intra-arterial thrombectomy for acute ischaemic stroke patients with active cancer.

BACKGROUND AND PURPOSE: This study aimed to evaluate the efficacy of intra-arterial thrombectomy (IAT) and prognosis for acute ischaemic stroke patients with active cancer. METHODS: We retrospectively reviewed 253 patients who underwent IAT within 24 h after stroke onset between January 2012 and August 2017. We classified the patients into active cancer (n = 26) and control groups (n = 227) and compared clinical data. Primary outcome was a modified Rankin scale score at 3 months with ordinal logistic regression (shift analysis). RESULTS: Initial National Institutes of Health Stroke Scale (NIHSS) and rate of successful recanalisation did not differ between groups, but the active cancer group showed poor outcomes at 3 months on shift analysis (P = 0.001). The independent predictors of poor prognosis were age [adjusted common odds ratio (aOR) 1.03, 95% confidence interval (CI) 1.01-1.05], baseline NIHSS (aOR 1.14, 95% CI 1.09-1.19), baseline C-reactive protein level (aOR 1.14, 95% CI 1.03-1.25), any cerebral haemorrhage (aOR 1.92, 95% CI 1.21-3.06), and active cancer (aOR 2.35, 95% CI 1.05-5.25). Mortality at 90 days was 30.8% in the cancer group and 8.8% in the control group (P = 0.003). CONCLUSIONS: Although baseline characteristics and recanalisation rate after IAT up to 24 h after stroke onset were similar between acute ischaemic stroke patients with active cancer and without any cancer, stroke-related death and short-term outcome were significantly poorer in patients with active cancer than the controls. Post-procedural haemorrhage and active cancer itself were independent predictors of a decrease in functional independence at 3 months.

The Impact of Cerebral Atherosclerosis According to Location on Prognosis after Coronary Artery Bypass Grafting.

BACKGROUND: In the previous prospective observational study, we found that cerebral atherosclerosis is an independent predictor of acute stroke after coronary artery bypass grafting (CABG). However, it is unknown whether intracranial cerebral atherosclerosis (ICAS) is important as much as extracranial cerebral atherosclerosis (ECAS) in estimating the risk of post-CABG adverse events. Extending the previous study, we aimed to investigate the immediate and long-term prognostic value of the location of cerebral atherosclerosis in CABG patients. METHODS: This follow-up study of previously reported prospective cohort included 1,367 consecutive patients who received CABG between 2004 and 2007. All patients underwent preoperative magnetic resonance angiography (MRA) to assess intracranial and ECAS, both defined by significant steno-occlusion (≥50%). Participants were classified into 4 groups according to the location of cerebral atherosclerosis: no cerebral atherosclerosis, ECAS only, ICAS only, and ECAS + ICAS. Post-CABG stroke within 14 days (immediate outcome) and mortality (long-term outcome) following CABG were compared between the groups. Survival data for all participants through June 2016 were obtained from the Korean National Registry of Vital Statistics. The Cox proportional hazards model was used to estimate the hazard ratio (HR) of post-CABG stroke and mortality; patients lacking cerebral atherosclerosis were defined as the reference group. RESULTS: The median follow-up duration after CABG was 9.2 years (interquartile range 8.4-10.2 years). Of the participants, 278 (20.3%) patients had ICAS only, while 269 (19.7%) and 347 (25.4%) showed ECAS only and ECAS + ICAS, respectively, in their preoperative MRA. Having ICAS only (HR 5.07; 95% CI 1.37-18.75; p = 0.015) and having ECAS + ICAS (HR 8.43; 95% CI, 2.48-28.61; p = 0.001) independently predicted the immediate stroke, whereas being with ECAS only did not (HR 1.71; 95% CI 0.35-8.50; p = 0.509). Conversely, ICAS-only status was not independently associated with long-term mortality (HR 1.22; 95% CI 0.90-1.65; p = 0.207), whereas ECAS-only status (HR 1.42; 95% CI 1.05-1.90; p = 0.021) and ECAS + ICAS status (HR 1.58; 95% CI 1.20-2.07; p = 0.001) showed independent associations. CONCLUSIONS: Over 10 years of follow-up, cerebral atherosclerosis significantly associated with the development of adverse outcomes after CABG. The prognostic value of ICAS might be different from that of ECAS; immediate post-CABG stroke was more closely associated with ICAS, whereas there was a closer association between long-term post-CABG mortality and ECAS.

Changes in the Common Carotid Artery after Radiotherapy: Wall Thickness, Calcification, and Atherosclerosis.

BACKGROUND AND PURPOSE: Since the long-term survival rate has improved in laryngeal cancer patients who receive radiotherapy, concerns about postradiation complications (including carotid atherosclerosis) have increased. We followed changes in the common carotid artery (CCA) after radiotherapy and identified the underlying risk factors. METHODS: Consecutive patients with laryngeal cancer who underwent radiotherapy between January 1999 and December 2009 and who had received computed tomography (CT) both pre- and postradiotherapy were enrolled. Changes in the wall thickness and in the vessel and lumen areas as well as the presence of calcification or atherosclerosis were investigated. Demographics and risk factors were compared between patients with and without atherosclerosis at follow-up CT. RESULTS: In total, 125 patients were enrolled. The wall thickness had increased and the lumen area had decreased several months after radiotherapy. These changes were not associated with vascular risk factors and were not progressive. Calcification and atherosclerosis were observed in 37 (29.6%) and 71 (56.8%) patients, respectively. Diabetes was associated with calcification (p=0.02). The prevalence of hyperlipidemia was higher in patients with atherosclerosis (28.2% vs. 11.1%, p=0.02) and for a longer period postradiation [62.7±32.1 vs. 40.0±24.2 months (mean±SD), p<0.001]. Atherosclerosis occurred mostly in the middle portion of the CCA (n=31, 24.6%), followed by the proximal CCA at the intrathoracic level (n=26, 20.6%) and the distal CCA (n=6, 4.8%). Positive remodeling was also observed, but this was less common in patients with calcification (p=0.02). CONCLUSIONS: Various types of postradiation changes occur in the CCA and can be easily observed in postradiation CT. The prevalence and burden of postradiation atherosclerosis increased in a close relationship with baseline cholesterol levels and the time after radiotherapy. Postradiation atherosclerosis was observed at unusual sites of the CCA.

Intracranial Aneurysm Is Associated with High Intracranial Artery Tortuosity.

BACKGROUND: Although intracranial aneurysms (IAs) are focal bulges of arterial walls, an uncharacterized predisposing factor that affects cerebral arteries may increase tortuosity of intracranial arteries in patients with IAs. METHODS: Subjects who underwent routine health examinations and magnetic resonance angiography at a university hospital health promotion center were enrolled. Age- and sex-matched control subjects were selected from among individuals who did not have IAs. Tortuosity of right and left middle cerebral arteries and basilar artery (BA) was measured. Distant factor [(arc/chord ratio × 100) - 100] was used to estimate tortuosity. Vascular risk factors and intracranial arterial tortuosities were compared between subjects with IAs and control subjects. Independent factors associated with intracranial artery tortuosity were also investigated. RESULTS: Of 18,954 (1.9%) subjects, 367 exhibited IAs. The prevalence of hypertension (P = 0.01) and current smoking (P = 0.01) were higher in subjects with IAs than in control subjects. The BA tortuosity was greater in subjects with IAs compared with control subjects (9.0 ± 8.1 vs. 5.5 ± 7.2; P < 0.001). In addition to hypertension, smoking, and absence of coronary artery disease, BA tortuosity (P < 0.001) was independently associated with presence of IAs. The presence of IA (P < 0.001) and absence of coronary artery disease (P = 0.002) were independently associated with high BA tortuosity. CONCLUSIONS: Patients with IAs exhibit a more tortuous BA. A predisposing factor weakening the cerebrovasculature in patients with IAs may exist and may manifest as high tortuosity of intracranial arteries.

Intracranial Pressure Soon After Hemicraniectomy in Malignant Middle Cerebral Artery Infarction.

BACKGROUND: Decompressive hemicraniectomy reduces secondary brain injury related to brain edema and increased intracranial pressure (ICP) in patients with malignant middle cerebral artery infarction (MMI). However, a substantial proportion of patients still die despite hemicraniectomy due to refractory brain swelling. OBJECTIVE: We aim to investigate whether ICP measured immediately after hemicraniectomy may indicate decompression effects and predict survival in patients with MMI. METHODS: We included 25 patients with MMI who underwent ICP monitoring and brain computed tomography within the first hour of hemicraniectomy. Midline shifts were measured as radiological surrogates of decompression. The Glasgow Coma Scale and pupillary enlargements during the first day after hemicraniectomy were assessed as clinical surrogates of decompression. Long-term survival status at 6 months was used as the final outcome. We analyzed the relationships between early ICP and findings of midline shift, Glasgow Coma Scale, pupillary enlargement, and survival. RESULTS: Initial ICP was correlated with mean ICP ( P < .001) and maximal ICP ( P < .001) during the first postoperative day. Intracranial pressure was associated with midline shifts ( P = .009), lower Glasgow Coma Scale scores ( P = .025), and the pupillary enlargement ( P = .015). Sixteen (64.0%) patients survived at 6 months. In a Cox proportional hazard model, elevated ICP was associated with mortality at 6 months (hazard ratio: 1.13; 95% confidence interval: 1.03-1.24; P = .008). CONCLUSION: Increase in ICP soon after hemicraniectomy was associated with midline shift, poor neurological status, and mortality in patients with MMI. Measurements of ICP soon after hemicraniectomy may permit earlier interventions as well as more refined clinical assessments.

Prognostic Significance of Troponin Elevation for Long-Term Mortality after Ischemic Stroke.

BACKGROUND AND PURPOSE: Troponin, a marker of myocardial injury, frequently increases and is related with poor outcome in ischemic stroke patients. However, the long-term outcome of this elevation remains uncertain. We, therefore, investigated the prognostic significance of troponin elevation for long-term mortality, and explored factors affecting troponin elevation after ischemic stroke. METHODS: We retrospectively analyzed the medical data of stroke patients who were admitted within 24 hours of symptom onset and underwent a serum cardiac troponin I test at admission during a five-year period. Information on mortality as the outcome was obtained from the National Death Certificate system. RESULTS: A total of 1,692 patients were eligible for inclusion with 33 months of median follow-up. Troponin elevation that exceeded the 99th percentile (>0.04 ng/mL) of values was detected in 166 patients (9.8%). After adjusting for baseline characteristics, troponin elevation was associated with previous ischemic heart disease and congestive heart failure, comorbid atrial fibrillation and active cancer, and increased National Institutes of Health Stroke Scale score. Patients with troponin elevation had a high risk of overall death (hazard ratio [HR] 1.83, 95% confidence interval [CI] 1.40-2.40), including stroke-related (HR 1.71, 95% CI 1.14-2.55), cardiac-related (HR 3.17, 95% CI 1.49-6.74), and cancer-related (HR 1.98, 95% CI 1.14-3.45) death than those without troponin elevation. CONCLUSIONS: Troponin elevation in the acute stage of ischemic stroke was associated with long-term mortality, mainly due to increased stroke- and cancer-related death in the first year and cardiacrelated death in the later period.

Comparison of 3D magnetic resonance imaging and digital subtraction angiography for intracranial artery stenosis.

OBJECTIVES: To compare three-dimensional high-resolution magnetic resonance imaging (3D HR-MRI) and digital subtraction angiography (DSA) for diagnosing and evaluating stenosis in the entire circle of Willis. METHODS: The study included 516 intracranial arteries from 43 patients with intracranial artery stenosis (ICAS) who underwent both 3D HR-MRI and DSA within 1 month. Two readers independently diagnosed atherosclerosis, dissection, moyamoya disease and vasculitis, rated their diagnostic confidence for each vessel and measured the luminal diameters. Reference standard was made from clinico-radiologic diagnosis. Diagnostic accuracy, diagnostic confidence, the degree of stenosis and luminal diameter were assessed and compared between both modalities. RESULTS: For atherosclerosis, 3D HR-MRI showed better diagnostic accuracy (P = .03-.003), sensitivity (P = .006-.01) and positive predictive value (P ≤ .001-.006) compared to DSA. Overall, the readers were more confident of their diagnosis of ICAS when using 3D HR-MRI (reader 1, P ≤ .001-.007; reader 2, P ≤ .001-.015). 3D HR-MRI showed similar degree of stenosis (P > .05) and higher luminal diameter (P < .05) compared to DSA. CONCLUSIONS: 3D HR-MRI might be useful to evaluate atherosclerosis, with better diagnostic confidence and comparable stenosis measurement compared to DSA in the entire circle of Willis. KEY POINTS: • 3D HR-MRI showed better diagnostic accuracy for atherosclerosiscompared to DSA • 3D HR-MRI showed better overall diagnostic confidence for stenosiscompared to DSA • 3D HR-MRI and DSA showed similar degree of stenosis.

Reduction of Midline Shift Following Decompressive Hemicraniectomy for Malignant Middle Cerebral Artery Infarction.

BACKGROUND AND PURPOSE: Hemicraniectomy is a decompressive surgery used to remove a large bone flap to allow edematous brain tissue to bulge extracranially. However, early indicators of the decompressive effects of hemicraniectomy are unclear. We investigated whether reduction of midline shift following hemicraniectomy is associated with improved consciousness and survival in patients with malignant middle cerebral artery infarctions. METHODS: We studied 70 patients with malignant middle cerebral artery infarctions (MMI) who underwent hemicraniectomies. Midline shift was measured preoperatively and postoperatively using computed tomography (CT). Consciousness level was evaluated using the Glasgow Coma Scale on postoperative day 1. Patient survival was assessed six months after stroke onset. RESULTS: The median time interval between preoperative and postoperative CT was 8.3 hours (interquartile range, 6.1-10.2 hours). Reduction in midline shift was associated with higher postoperative Glasgow Coma Scale scores (P<0.05). Forty-three patients (61.4%) were alive at six months after the stroke. Patients with reductions in midline shifts following hemicraniectomy were more likely to be alive at six months post-stroke than those without (P<0.001). Reduction of midline shift was associated with lower mortality at six months after stroke, after adjusting for age, sex, National Institutes of Health Stroke Scale score, and preoperative midline shift (adjusted hazard ratio, 0.71; 95% confidence interval, 0.62-0.81; P<0.001). CONCLUSIONS: Reduction in midline shift following hemicraniectomy was associated with improved consciousness and six-month survival in patients with MMI. Hence, it may be an early indicator of effective decompression following hemicraniectomy.

Nonatheroscleotic Isolated Middle Cerebral Artery Disease May Be Early Manifestation of Moyamoya Disease.

BACKGROUND AND PURPOSE: Middle cerebral artery steno-occlusive disease (MCAD) is not an uncommon cause of ischemic stroke in young Asians. Aside from atherosclerosis, the pathogenesis of MCAD include various nonatherosclerotic vasculopathies, most of which are yet to be defined. This study investigated the pathogenesis of symptomatic isolated MCAD in young Asian patients using high-resolution magnetic resonance imaging (HR-MRI) and mutation analysis of RNF213. METHODS: Patients aged <60 years with stroke or transient ischemic attack caused by MCAD were prospectively enrolled. Patients with a confirmed diagnosis of moyamoya disease, dissection, and vasculitis; with significant steno-occlusion in cerebral arteries other than the MCA; or with high-risk cardioembolic source were excluded. Using high-resolution MRI, patients were classified into an atherosclerosis group and a nonatherosclerosis group. RESULTS: Eighty-one patients were enrolled, 45 (56.6%) in the atherosclerosis and 36 (44.4%) in the nonatherosclerosis group. The nonatherosclerosis group was significantly younger (P=0.013), had a smaller number of vascular risk factors (P=0.001), showed a lower homocysteine level (P<0.001), thinner intima-media thickness (P=0.006), and had more frequent heterozygotes at RNF213 (P=0.045) than the atherosclerosis group. Diffusion-weighted image lesion pattern showed no significant differences in assumed stroke mechanisms between the 2 groups. CONCLUSIONS: Nonatherosclerotic pathogenesis are common in young Asians with symptomatic isolated MCAD. Clinical findings, high-resolution MRI features, and results of RNF213 mutation analysis suggest that moyamoya disease is responsible etiologically for a significant portion of nonatherosclerotic lesions. Symptomatic isolated MCAD may be an early manifestation of moyamoya disease in young Asian adults.

A Retrospective 10-Year, Single-Institution Study of Carotid Endarterectomy with a Focus on Elderly Patients.

BACKGROUND AND PURPOSE: This study evaluated the outcome following surgery for carotid artery stenosis in a single institution during a 10-year period and the relevance of aging to access to surgery. METHODS: Between January 2001 and December 2010, 649 carotid endarterectomies (CEAs) were performed in 596 patients for internal carotid artery occlusive disease at our institution; 596 patients received unilateral CEAs and 53 patients received bilateral CEAs. Data regarding patient characteristics, comorbidities, stroke, mortality, restenosis, and other surgical complications were obtained from a review of medical records. Since elderly and high-risk patients comprise a significant proportion of the patient group undergoing CEAs, differences in comorbidity and mortality were evaluated according to age when the patients were divided into three age groups: <70 years, 70-79 years, and ≥80 years. RESULTS: The mean age of the included patients was 67.5 years, and 88% were men. Symptomatic carotid stenosis was observed in 65.7% of patients. The rate of perioperative stroke and death (within 30 days of the procedure) was 1.84%. The overall mortality rate was higher among patients in the 70-79 years and >80 years age groups than among those in the <70 years age group, but there was no significant difference in stroke-related mortality among these three groups. CONCLUSIONS: CEA over a 10-year period has yielded acceptable outcomes in terms of stroke and mortality. Therefore, since CEA is a safe and effective strategy, it can be performed in elderly patients with acceptable life expectancy.

Risk Factors Associated With the Presence of Unruptured Intracranial Aneurysms.

BACKGROUND AND PURPOSE: With the increased investigation of cerebral arteries using magnetic resonance angiography in the general population, the detection of unruptured intracranial aneurysms (UIAs) has increased. Understanding the distribution and factors associated with UIAs might be helpful for understanding the pathomechanism. METHODS: Subjects who underwent magnetic resonance angiography with a health examination at the Health Screening and Promotion Center were enrolled. The incidence and risk factors of UIAs (age, sex, hypertension, diabetes mellitus, smoking, alcohol, and coronary artery disease) were investigated by comparing patients with and without UIAs. These risk factors were also investigated by the UIA location, distal internal carotid artery, anterior cerebral artery and middle cerebral artery (MCA), MCA bifurcation, anterior and posterior communicating artery, and posterior circulation. RESULTS: Among 187 166 subjects who received health examination, 18 954 underwent magnetic resonance angiography. Of them, 367 (1.93%) had UIAs. Age (odds ratio [OR], 1.02; P=0.003), women (OR, 2.00; P<0.001), hypertension (OR, 2.21; P<0.001), smoking (OR, 1.66; P=0.001), and coronary artery disease (OR, 0.23; P<0.001) were independently associated with the presence of UIAs. Hypertension was associated with most UIAs, except for those located at sidewalls (anterior cerebral artery and MCA). MCA aneurysms were associated with old age and smoking. Distal internal carotid artery, posterior communicating artery, and MCA-bifurcation aneurysms were associated with female sex. Anterior communicating artery aneurysms were associated with smoking and alcohol. Posterior circulation UIAs were only associated with hypertension. Coronary artery disease was negatively associated with anterior circulation aneurysms. CONCLUSIONS: The risk factors for UIAs differ by their location, compared with the control. Interestingly, the presence of coronary artery disease was protective against the presence of UIAs.

Isolated MCA disease in patients without significant atherosclerotic risk factors: a high-resolution magnetic resonance imaging study.

BACKGROUND AND PURPOSE: Diagnosis of intracranial artery atherosclerosis remains often uncertain. The high-resolution magnetic resonance imaging (HR-MRI) enables vessel wall assessment for more precise diagnoses. The aim of the present study was to investigate the etiologies of middle cerebral artery steno-occlusive disease in young adult patients with few atherosclerotic risk factors using HR-MRI. METHODS: We prospectively studied patients who visited a tertiary hospital in Seoul, Korea, and had (1) unilateral middle cerebral artery disease (≥50% stenosis or occlusion), (2) were ≤55 years old and had no or minimal (≤1) atherosclerotic risk factors. We excluded patients with a confirmed diagnosis of Moyamoya disease, vasculitis, or dissection and those having emboligenic sources. A presumptive diagnosis was made based on HR-MRI findings, and patients were categorized as HR-athero (atherosclerotic disease), HR-MMD (Moyamoya disease), HR-dissection, or HR-vasculitis. RESULTS: Among 95 patients analyzed, 26 (27.4%) had HR-athero who were more often male (P=0.004), smokers (P=0.018), and had focal stenosis (P=0.003) than others.As compared with the HR-athero patients, 29 HR-MMD patients were more often female (P<0.001) and more often had occlusive lesions (P=0.001) and nonfocal stenosis (P<0.001). The 22 HR-dissection patients tended to have hypertension less often, and the 13 HR-vasculitis patients were younger (P=0.004) and tended to have nonfocal stenosis. [corrected]. CONCLUSIONS: In our cohort of young patients with minimal risk factors, atherosclerosis seems to be an uncommon pathology of middle cerebral artery stenosis. HR-MRI aids us to make a more reliable diagnosis.

Validity of acute stroke lesion volume estimation by diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomographic Score depends on lesion location in 496 patients with middle cerebral artery stroke.

BACKGROUND AND PURPOSE: Alberta Stroke Program Early Computed Tomographic Score (ASPECTS) has been used to estimate diffusion-weighted imaging (DWI) lesion volume in acute stroke. We aimed to assess correlations of DWI-ASPECTS with lesion volume in different middle cerebral artery (MCA) subregions and reproduce existing ASPECTS thresholds of a malignant profile defined by lesion volume ≥100 mL. METHODS: We analyzed data of patients with MCA stroke from a prospective observational study of DWI and fluid-attenuated inversion recovery in acute stroke. DWI-ASPECTS and lesion volume were calculated. The population was divided into subgroups based on lesion localization (superficial MCA territory, deep MCA territory, or both). Correlation of ASPECTS and infarct volume was calculated, and receiver-operating characteristics curve analysis was performed to identify the optimal ASPECTS threshold for ≥100-mL lesion volume. RESULTS: A total of 496 patients were included. There was a significant negative correlation between ASPECTS and DWI lesion volume (r=-0.78; P<0.0001). With regards to lesion localization, correlation was weaker in deep MCA region (r=-0.19; P=0.038) when compared with superficial (r=-0.72; P<0.001) or combined superficial and deep MCA lesions (r=-0.72; P<0.001). Receiver-operating characteristics analysis revealed ASPECTS≤6 as best cutoff to identify ≥100-mL DWI lesion volume; however, positive predictive value was low (0.35). CONCLUSIONS: ASPECTS has limitations when lesion location is not considered. Identification of patients with malignant profile by DWI-ASPECTS may be unreliable. ASPECTS may be a useful tool for the evaluation of noncontrast computed tomography. However, if MRI is used, ASPECTS seems dispensable because lesion volume can easily be quantified on DWI maps.

New brain infarcts on magnetic resonance imaging after coronary artery bypass graft surgery: lesion patterns, mechanism, and predictors.

OBJECTIVE: New brain infarcts after coronary artery bypass graft (CABG) are markedly more frequent than clinically evident stroke and have been proposed as a surrogate marker of postprocedural stroke. We sought to investigate the lesion patterns, mechanisms, and predictors of new brain infarction after CABG surgery. METHODS: This was a prospective pre- and postoperative brain magnetic resonance imaging (MRI) study in consecutive patients who underwent isolated CABG. Preoperative MRI included diffusion-weighted imaging (DWI) and magnetic resonance angiography. DWI was repeated on postoperative day 3. Clinical variables, intraoperative findings, and laboratory findings were compared between patients with and without new brain infarcts on DWI. RESULTS: Of a total of 127 included patients, 35 (27.6%) showed new brain infarcts on DWI. Most lesions were clinically silent, located in the cortical territory (80%), small (<1.5cm) in diameter (89%), and not related to the underlying cerebral arterial abnormality (80%). Old age (odds ratio [OR] = 1.09, 95% confidence interval [CI] = 1.03-1.15), use of cardiopulmonary bypass (OR = 3.12, 95% CI = 1.13-8.57), a moderate to severe aortic plaque (OR = 21.17, 95% CI = 2.01-222.58), and high levels of high-sensitivity C-reactive protein (OR = 1.35, 95% CI = 1.08-1.70) were independent predictors of new brain infarction. INTERPRETATION: Post-CABG new brain infarcts are mostly silent and cortically located. Old age, aortic arch atherosclerosis, use of cardiopulmonary bypass, and systemic inflammatory response may contribute to the pathogenesis of post-CABG new brain infarcts.